1. Field of the Invention
This invention relates to a connector for a leadless IC having a number of conductive pads (terminals) on its lower surface.
2. Brief Description of the Prior Art
In the above-mentioned leadless IC measuring socket, etc., a mount-to-contact type connector has heretofore been used. This mount-to-contact type connector, as represented by, for example, Japanese Utility Model Publication No. Hei 2-31790, includes a contact having a horizontal U-shaped contact piece, the horizontal U-shaped contact piece being provided with a male terminal extending from a lower arm thereof, the arm being flexed when a leadless IC package with a conductive pad disposed on a lower surface is mounted on a free end of an upper arm of the horizontal U-shaped contact piece and a downward push-down force is exerted on the IC in order to obtain a contact pressure with the conductive pad by reaction thereof.
Also, in Japanese Utility Model Early Laid-open Publication No. Sho 63-25467, a movable terminal is nested in a sleeve terminal having a male terminal and resiliently held by a coil spring disposed within the sleeve terminal, the coil spring being compressed when its distal end portion exposed through an opening portion of the sleeve terminal is pushed by a conductive pad, etc. in order to obtain a contact pressure by reaction thereof.
However, the largest problem for the former type structure is that since the horizontal U-shaped contact piece extends outward from two or four peripheral sides of IC, the connector becomes large in outer size and thus inferior in mounting efficiency. Furthermore, although the contact can be used, without any trouble, for an IC having conductive pads arranged along the edge portion thereof, it becomes difficult to use for IC having a number of conductive pads which are arranged in several rows in a lattice pattern as shown in FIG. 8 herein.
In the latter sleeve type contact, there are problems that the number of component parts is increased, the sleeve terminal is required to be highly accurately cut, and the cost is high. Moreover, the operating force required for pushing the conductive pad against the movable terminal becomes excessively large. In addition, since the movable terminal is nested in the sleeve terminal, miniaturization and high density arrangement are limited due to restriction of the diameter thereof.